A
abscess A localized INFECTIONcontaining pus, a
fluid-based collection of white BLOODcells, BACTE-
RIA, and the debris resulting from the IMMUNE SYS-
TEM’s efforts to fight the infection. Though an
abscess may cause severe PAINand compromise the
function of organs in which it occurs, an abscess
represents the success of the immune system to
contain and enclose the infection. An abscess can
develop anywhere in the body. Symptoms vary
with the abscess’s location though typically
include pain and swelling in the area of the infec-
tion. There often is FEVERas well. An abscess on
the SKINor near the surface of the skin may form a
red nodule or an open sore. Treatment is ANTIBI-
OTIC MEDICATIONSwhen the infection is bacterial. A
deep, internal abscess may require surgery to
drain the pus so HEALINGcan take place.
See also BARTHOLIN’S CYST; FURUNCLE; HEPATIC
ABSCESS; LUNG ABSCESS; PERITONSILLAR ABSCESS.
adenovirus A VIRUSfamily that causes INFECTION
of mucous membrane tissues throughout the
body. Adenoviruses are responsible for a wide
range of illness including upper respiratory infec-
tion, viral CONJUNCTIVITIS, GASTROENTERITIS, and URI-
NARY TRACT INFECTION (UTI). These infections
primarily affect children age 10 and younger.
Infection with one adenovirus confers immunity
to that strain of virus; vulnerability to infection
with other strains of adenovirus remains. Adeno-
viruses are highly contagious and are particularly
adept at mutating and adapting. They primarily
spread through
- person-to-person direct contact, such as touch-
ing - indirect contact, such as by touching doorknobs
or furniture a person infected with the virus
has touched, leaving viral particles behind, or
by handling tissues an infected person uses- airborne particles, such as enter the air via
sneezing and coughing - fecal contamination, such as through changing
diapers or lack of HAND WASHINGafter using the
bathroom
The INCUBATION PERIOD(time from exposure to
onset of symptoms) is usually less than 10 days
and often only 2 or 3 days. Adenoviral infection
seldom causes serious illness and is self-limiting
(goes away on its own after running its course).
Symptoms depend on the location of the infec-
tion. The doctor may take mucus samples to test
for the presence of BACTERIA, as the symptoms of
bacterial and viral infections are often similar.
Bacterial infection requires antibiotic therapy;
ANTIBIOTIC MEDICATIONS are not effective against
viral infections. Treatment for adenoviral infection
targets symptom relief. Because adenoviruses are
so pervasive, preventing infection is nearly impos-
sible. The most important step to minimize the
risk for infection is frequent hand washing with
soap and warm water. People who are IMMUNO-
COMPROMISEDshould avoid indoor crowds to the
extent possible to reduce their exposure to people
infected with adenoviruses.
See also COLDS; DIARRHEA; FOODBORNE ILLNESSES;
SNEEZE/COUGH ETIQUETTE.amebiasis A parasitic INFECTIONof the gastroin-
testinal tract. The PARASITEresponsible is Entamoeba
histolytica, a single-cell organism (an ameba) that
enters the body by drinking water or eating food
that contains E. histolyticain cyst form. The cyst is
a protective encasing within which the ameba306